Data replication for backup and recovery purposes is generally achieved by creating a shadow copy of a storage volume, e.g., in a server. Such replication may be done, for example, using Volume Shadow Copy Service (VSS) utility of the Windows™ operating system. A VSS command may be issued to take a volume snapshot periodically such as, for example, every fifteen minutes, to ensure that all application data and data in a cache memory in the file system are flushed to disk.
However, such volume-level snapshot and replication techniques may not be usable for operating systems such as UNIX, Linux, for example. Additionally, volume-level snapshots may not provide specific structural and/or organizational details of the file system maintained within the operating system. Accordingly, in the event where data of only particular files are changed due to one or more operations, volume-level snapshots may not provide enough resolution to identify only the specific modified files or modified data blocks in the files for replication. Rather, in the absence of a sense of the file system, data of the complete volume may have to be replicated, or in the case where operational changes on some specific files are to be reversed, data of the complete replicated volume (and not just that of the specific files) may have to be used for data restoration. This may result in additional processing burden and increased network traffic within the data replication system.
Additionally, even if data replication is performed by comparing two snapshots on a file-by-file or directory-by-directory basis, and sending the differences to a backup system or server, the replication process may be very slow and data-traffic intensive, thereby negatively impacting the performance of the replication system.
Thus, to address the above-discussed problems, it is desirable to develop and provide an improved replication process that may be implemented on wide range of operating systems without slowing down, or otherwise negatively impacting the replication process.